Feed device



March 16, 1943. c. H. SCHLESMAN FEED DEVICE Filed Nov. 4, 1941 2 Sheets-Sheet 2 A? CARI-E704 .SCl/LESMA/Y INVENTOR ATTORNEY Patented Mar. 16, 1943 FEED DEVICE Carleton H. Schlesman, Camden, N. J., assignor to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation of York Application November 4, 1941-, erial No. 417,862

' 11 Claims.

This invention relates to apparatus for feeding solid material and is particularly concerned with devices for feeding solid material tively small size downwardly.

In many types of process operation, it is desired to feed a powdered or finely divided granular material into processing equipment ata fairly constant rate. Such feed is rendered difllcultbecause the nature of many materials so fed causes them to cling together or bridge in feed pipes either by mechanical means or by reason of electrostatic charges. An example is the feeding of clay type-catalysts to a chamber wherein the granular material promotes cracking of hydrocarbon vapors or is regenerated by burning off carbonaceous deposits formed in a cracking or other operation. In such cases, the catalyst must be fed through a vapor seal, usually against a pressure in excess of atmospheric.

The present invention contemplates apparatus for preventing the difiiculties noted above and in its preferred embodiment the invention contemplates provision of apparatus which, in addition to means for preventing erratic feed resulting from characteristics of the solid matter fed, results in an eflicient vapor seal which renders it possible to feed continuously at a desired rate against substantial pressure.

In its simple embodiments, the invention comprises means within a vertical feed tube to cause breaking of stoppages arising from bridging of the material in the tube. Essentially these means are a plurality of vanes hingedly mounted on a vertically reciprocating rod in such manner that they may either lie in. a downward position against the rod, or, under the influence of obstructions to free passage of the vanes, on the down stroke, rise .to a position at a substantial angle to the rod at which position further movement of the vane about its hinge joint is arrested by a suitable stop member. Apparatus of this type assures sufliciently uniform flow of the solids while having the advantage over such devices as screw conveyors that the load on the power supply is simply that required for reciprocation of the rod running free except when a stoppage occurs. This feature of automatic unloading of the power supply whenever power is not required is a very material advantage.

According to a preferred embodiment of the invention, a somewhat similar device is used for positive feed of finely divided solid matter against a fluid pressure within the chamber or of relaother vessel :to which the solids are supplied. Escape of substantial quantities of the fluids under pressure through the feed device is inhllbited by establishing a column of the solids highly resistant to fluid flow. This embodiment provides for replacement of gas in the voids of the body of solid matter by the fluid in the chamber supplied, venting the replaced gas, probably together with tracesof the said fluid, from the device.

The nature and further objects of the invention appear more clearly from the following detailed discussion of two modifications thereof as shown in the attached drawings, wherein:

Figure l is an elevation, in partial section, of one form of the apparatus of this invention;

Figure 21s a plan viewof the vane assembly with the vanes in their maximum extended position;

Figure 3 is a sectional view on line 3-3 of Figure 2; and

Figure 4 is a view in vertical section of a modified form of the apparatus adapted for feeding solid .matter against substantial fluid pressure withventing of gases.

As seen in Figure 1, a hopper I0 is provided to supply a solid material in finely divided form, say 30'mesh or finer, through a feed tube II, at rate dependent upon the dimensions of the tube, to a chamber I2. Within and coaxial with the tube II is a rod l3, mounted for reciprocation in brackets l4 and I5. Suitable means-are provided to reciprocate rod I3. Along the length of rod l3 within the tube ll area plurality of vanes, l8, hingedly mounted on rod I3 for movement about horizontal axes.

Each of the vanes I8 is semi-circular in outline and a pair of vanes, l8, mounted with complementary vanes on opposite sides of the rod 13, cooperate to define a disc of slightly less diameter than the diameter of the tube. According to the hinging arrangement shown in Figures 2 and 3, a pin l9, passed through rod I3, is employed as the element about which the vanes l8 rotate by'virtue of having extensions of their straight edges turned about the pin |9.- Along the edge of each vane l8, a stop member 20 is provided to limit upward movement of the vane beyond that point at which the vane is designed to bears against rod I3 when the vane is in the fully extended position. It is preferred, however, that additional means such as lugs 20 either in the form shown or arcuate to fit rod l3, be provided.

In a typical use of the device of Figure 1,'it is desired to feed clay into a clay burner or catalytic cracking chamber from an elevated hopper through a vertical feed pipe about 6 inches in diameter and twenty feet long. In operation, it is found that the flow of solids is erratic due to bridging of the material which may be caused by the presence of" a small amount of moisture, sticking of the material itself, or actual los of feed with air leaving the same as a result of the formation of voids in the flowing clay through introduction of gases at the point of discharge. When the device of 'Figure 1 is used in this situa- 4 tion, vanes are provided along the rod |3 at intervals of about 2 feet. The rod is reciprocated at a rate such that the maximum speed on the down stroke is less than the linear velocity of the flowing clay. During normal operation the vanes will hang downwardly from their hinge joints and the clay will flow past in the manner for which the unit is designed. If, however, an obstruction occurs and the flow of clay is thereby slowed up, the vanes will open on the down stroke because they are moving faster than the clay. Positive force will be applied by those vanes in the region of reduced clay speed to push the clay past and break up the obstructive bridging. Vanes other than those mentioned would remain in the closed position. On the upward return stroke all vanes will close and normal flow will be resumed.

It will be apparent that the specific details of construction shown and described are not limiting of the invention. For example, the shape as well as the size of the vanes relative to the feed tube may be extensively modified within thescope of the invention. Power conservation above that provided by the automatic unloading properties of the device may be realized by using the present device in a battery of similar feed units, each at a different portion of the cycle of operation, in order that power consumption for overcoming gravitational and inertia forces shall cancel out of the load carried .by the prime mover.

The above described apparatus may be used to admit finely divided solids of the class mentioned to a chamber under pressure by reason of the fact that the long tube provides a column of solids having high resistance to escape of gases which are present in the pressure chamber. Better results in this respect are obtained by use of a device in the nature of that shown in Figure 4.

I In this apparatus the feed tube :proper is defined by a series of successive coaxial tubes 2| within a casing 22 along the axis of which passes the rod l3 bearing the vanes l8 and associated stops 20 as described above. The length of the tube is such that this finely divided material might stand at about the mid-point thereof it the system were'at equilibrium conditions. In order to provide flow several additional feet of clay are required to develop sufilcient pressure head to overcome frictional losses. Again in this embodiment the vanes are utilized primarily to insure flow at a desired rate and are normally in closed position.

The bottom of the hopper 0 feeds directly into the topmost tube 2 I, which discharges to the tube 2| immediately therebelow. The upper end of each tube 2| below the uppermost is extended upward and outward about the tube 2| immediately above it to provide an annular space open to but not within the zone of, flow through the feed conduit. A similar annular space is provided by the casing 22 in cooperation with the lowermost tube 2| By reason of the back pressure against the column exerted by gases within the chamber l2, clay will be forced up into each of these annular spaces to a height characteristic of the pressure conditions in the corresponding tube 2|. There will, of course, be fluctuation of this level as the rod I3 is reciprocated, but in general, a fairly definite average level will be main'iained in each annular space so long as such factors as pressure in the chamber l2, height of clay in the hopper l0 and the rate of reciprocation of rod 3 are maintained substantially constant. These annular spaces serve as vapor traps to remove gases from the mass of solid particles under the action of the vanes which come into operation whenever .a large void occurs in the column. At such times there is increased tendency for particles to move laterally into and out of the annular spaces and the gases will be passed to the portion of the ana plurality of feed tubes within and coaxial with said casing disposed successively along the length of said casing with a substantial space between adjacent ends of successive tubes, the uppermost of said tubes being provided with means to direct flow of solid material by gravity from said hopper into said first tube; the upper end of each other of said tubes being extended outwardly and upwardly to between the tube thereabove and said casing to form an annular space about said tube thereabove, means to vent gases from the upper portion of each of said annular spaces and the space between said casing and th lowermost of said tubes, a rod mounted for reciprocation longitudinally of said casing within said tubes, a plurality of vanes hingedly connected to said rod for relative movement about axes at tially vertical casing communicating with said hopper at its upper end and adapted at its lower end to be connected to means defining said zone for communication with said zone, a plurality of feed tubes within and coaxial with said casing disposed successively along the length of said casing with a substantial space between adjacent ends of successive tubes, the uppermost of said tubes beingprovided with means to direct flow of solid material by gravity from said hopper into said first tube, the upper end of each other of said tubes being extended outwardly and upwardly to between the tube thereabove and said casing to form an annular space about said tube thereabove, means to vent gases from the upper portion of each of said annular spaces and the space between said casing and the lowermost of said tubes, a rod mounted for reciprocation longitudinally of said casing within said tubes, a pluright angles to the axis of said rod and means to limit upward movement of said vanes relative to said rod.- l

3. In a device for feeding finely divided solid matter to a pressure zone, a hopper, a substantially vertical cylindrical casing communicating with said hopper at its upper end and adapted at its lower end to be connected to means defining said zone for communication with said zone, a plurality of feed tubes within and coaxial with said-casing disposed successively along the length of said casing with a substantial space between adjacent ends of successive tubes, the uppermost of said tubes being provided with means to direct flow of solid material by gravity from said hopper into said first tube, the upper end of each other of said'tubes being extended outwardly and upwardly to between the tube thereabove and said casing to form an-annula'r space about said tube thereabove and means to vent gases from the upper portion of each of said annular spaces and the space between said casing and the lowermost of said tubes.

4. In a device for feeding finely divided solid matter to a pressure zone, a hopper, a substantially vertical cylindrical casing communicating with said hopper at its upper end and adapted at its lower end to be connected to means defining said zone for communication with said zone, a-

plurality of feed tubes within and coaxialwith said casing disposed successively along the length of said casing with a substantial space between adjacent ends of successive tubes, the uppermost of said tubes being provided with means to direct flow of solid materialby gravity from said hopper into said first tube, the upper end of each other of said tubes being extended outwardly and upwardly to,between the tube thereabove and said casing to form an annular space about said tube thereabove, means to vent gases from the upper portion of each of said annular spaces and the space between said casing and th lowermost of said tubes a rod mounted for reciprocation longi-.

tudinally of saidcasing within said tubes, a plurality of vanes hingedly connected to said rod for relative movement about axes at substantially right angles to the axis of said rod and means to limit upward movement of said vanes relative to said rod, said vanes being mounted in pairs of opposed vanes, each pair being in extended position similar in outline to but slightly smaller than the internal cross-section of said tubes.

5. In a device for feeding finely divided solid matter to a pressure zone, a hopper, a substantially vertical casing communicating with said hopper at its upper end and adapted at its lower end to be connected to means defining said zone for communication with said zone, a plurality of feed tubes within and coaxial with said casing disposed successively along the length of said casing with a substantial space between adjacent ends of successive tubes, the uppermost of said tubes being'provided with means to direct flow of solid material by gravity from said hopper into said first tube, the upper end of each other of said tubes being extended outwardly and upwardly to between the tube thereabove and said casing to form an annular space about said tube thereabove, means to vent gases from the upper portion of each oi said annular spaces and the to limit upward movement of said vanes relative to said rod, said vanes being mounted in pairs of opposed vanes, each pair being in extended position similar in outline to but slightly smaller than the internal cross-section of said tubes.

6. In a device for feeding finely divided solid matter to a pressure zone, a hopper, a substantially vertical casing communicating with said hopper at, its upper end and adapted at its lower end to be connected to means defining said zone for communication with said zone, a plurality of feed tubes within and coaxial with said casing disposed successively along the length of said casing with a substantial space between adjacent ends of successive tubes, the uppermost of said tubes being provided with mean: to direct flow of solid material by gravity from said hopper inand the space between said casing and the low- I remost of said tubes. I I

7 In a device for feeding finely divided solid matter to a pressure zone, a hopper, a substantially vertical casing communicating with said hopper at its upper end and adapted at its lower end to be connected to means defining said zone for communication with said zone, a plurality of feed tubes within and coaxial with said casing disposed successively along the length of said casing with a substantial space between adjacent ends of successive tubes, the uppermost of said tubes being provided with means to direct flow of solid material by gravity from said hopper into said first tube, the upper end of each other of said tubes being extended outwardly and upwardly to between the tube'thereaboveand said casing to form an annular space about said tube thereabove, means to vent gases from the upper portion of each of said annular spaces and the space between said casing and the lowermost of said tubes, a rod mounted for reciprocation longitudinally of said casing within said tubes, a plurality of vanes hingedly connected to said rod for relative movement about axes at substantially right angles to the axis of said plurality of vanes hingedly connected to said rod for relative movement about axes at substantially right angles to the axis of said rod and means rod-and means to limit upward movement of said vanes relative tosaid rod to a position of said vanes substantially at right angles to said rod.

8. In 'a device of the class described, an elongated substantially vertical conduit, a rod mounted for reciprocation longitudinally of said conduit, a plurality of vanes hingedly connected to said rod for relative movement about axes at substantially right angles to said rod and means to limit upward movement of said vanes relative to said rod, said vanes being mounted in pairs of opposed vanes, each pair being in extended position similar in outline to but slightly smaller than the internal cross-section of said conduit.

9. In a device of the class described, an elongated substantially vertical cylindrical conduit, a rod mounted for reciprocation longitudinally of said conduit, av plurality of vanes hingedly connected to said rod for relative movement about axes at substantially right angles to said rod and means to limit upward movement of said vanes relative to said rod, said vanes being mounted in pairs of opposed vanes, each pair being in extended position similar in outline to but slightly smaller than the internal cross-section of said conduit.

10. In a device of the class described, an elongated substantially vertical conduit, 9. rod mounted for reciprocation longitudinally of said conduit, a" plurality of vanes hingedly connected to said rod for relative movement about axes at substantially right angles to said rod and means to limit upward movement of said vanes relative to said rod to a position of said vanessubstantially at right angles to said rod, said vanell being mounted in pairs of opposed vanes, each pair being in extended position similar in outline to but slightly smaller than the internal cross-section of said conduit.

11. In a device of the class described, an elongated substantially vertical conduit, a rod mounted for reciprocation longitudinally of said conduit, a plurality of vanes hingedly connected to said rod for relative movement about axes at substantially right angles to said rod and means to limit upward movement of said vanes relative to said rod, each of said vanes having its edge remote from said rod when at right angles to said rod shaped to substantially correspond to the inner surface of said conduit.

CARLETON n. SCI-ILESMAN. 

